Hi experts。
Could you pls help explain how to deal with unused ADC ports? Pull up or ground, what's the difference? Thanks.
This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
Hi experts。
Could you pls help explain how to deal with unused ADC ports? Pull up or ground, what's the difference? Thanks.
Hello Hangjie,
Realistically there are 2 categories of options: Connect to a known, nonzero voltage (VDD or VDD/2 preferred) or connect to GND.
Connecting to GND will result in nano-amps of current leakage out of the inputs because of the way the MUX is designed.
Connecting to VDD or VDD/2 results in no leakage but can be troublesome for layout. There is no need for pullup resistors but some customers decide to add resistors to limit input current if something happens to the VDD rail the resistors are connected to. So pull up resistors are for extra protection but not necessary.
Best,
-Cole